Waiting for async/await inside a task

It's discouraged to use Task.Factory.StartNew with async-await, you should be using Task.Run instead:

var t = Task.Run(
    async () =>
    {
        Foo.Fim();
        await Foo.DoBar();
    });

The Task.Factory.StartNew api was built before the Task-based Asynchronous Pattern (TAP) and async-await. It will return Task<Task> because you are starting a task with a lambda expression which happens to be async and so returns a task. Unwrap will extract the inner task, but Task.Run will implicitly do that for you.

For a deeper comparison, there's always a relevant Stephen Toub article: Task.Run vs Task.Factory.StartNew

It seems like I get desired functionality by Unwrap()ing the task. I'm not quite sure I get the reasoning behind this, but I suppose it works.

var t = Task.Factory.StartNew(
            async () =>
                {
                        Foo.Fim();
                        await Foo.DoBar();
                }).Unwrap();

edit: I've looked for ddescription of Unwrap(): Creates a proxy Task that represents the asynchronous operation of a Task<Task<T>> I thought this was traditionally what the task did, but if I need to call unwrap I suppose that's fine.